Oxygen potentials, oxygen diffusion coefficients and defect equilibria of nonstoichiometric (U,Pu)O

不定比(U,Pu)Oの酸素ポテンシャル、拡散係数及び欠陥平衡

加藤 正人   ; 渡部 雅  ; 松本 卓; 廣岡 瞬 ; 赤司 雅俊 

Kato, Masato; Watanabe, Masashi; Matsumoto, Taku; Hirooka, Shun; Akashi, Masatoshi

(U,Pu)Oの酸素ポテンシャルについて、最新の実験データベースを用い、欠陥化学に基づいて評価した。酸素分圧と定比組成からのずれxを解析し、点欠陥の生成エネルギを評価した。得られた欠陥反応の平衡定数を用いて、欠陥濃度、酸素ポテンシャル及び拡散係数の間の関係を記述した。

Oxygen potential of (U,Pu)O was evaluated based on defect chemistry using an updated experimental data set. The relationship between oxygen partial pressure and deviation in (U,Pu)O was analyzed, and equilibrium constants of defect formation were determined as functions of Pu content and temperature. Brouwer's diagrams were constructed using the determined equilibrium constants, and a relational equation to determine O/M ratio was derived as functions of O/M ratio, Pu content and temperature. In addition, relationship between oxygen potential and oxygen diffusion coefficients were described.